Hacker News Board Hacker News, browsed like a classic message board
Live data from Hacker News

Python coding interview challenges

github.com

Post reply on HN
Print view View original

51–60 of 252 posts

Re: Python coding interview challenges

#51

Post by gizmodo59 »

andrepd wrote: post #42
cauterized wrote: post #27

I see these challenges as a great way for excellent experienced developers to weed out incompetent companies. I'm a kick-ass get-things-done full-stack web engineer. I've never had to deal with one of these sorts of problems in my day to day work; and if I did, I'd just find an existing, tested, stable library that already handled them. A company that needs someone to solve these sorts of problems doesn't want me on…

It's not about actually having to implement these algorithms in your practical, day-to-day work. It's a challenge to test your reasoning and problem-solving ability in abstract, that you can administer in 15 minutes. You can't really test a candidate with real-world workloads, can you.

"reasoning and problem-solving ability in abstract"

Implementing a syntactically correct tic tac toe program on a whiteboard doesn't fit it. Plus many are comfortable in working behind the screen than to work in front of white board (real world)

Re: Python coding interview challenges

#52

Post by falcolas »

Somewhat of a tangent, but that "Distributed design" document gives me hives - with the lack of lines from "write" or "async write" back to the readers or cache. The taming of stale data would be a nightmare to manage when it suddenly starts to matter.

Also, where's the completed response caching layer? Nothing destroys performance (and hikes costs) like having to recompute every page response from raw data.

And that doesn't even touch my annoyance at shoehorning "federated architecture" to mean "sharding with a different algorithm".

Re: Python coding interview challenges

#54

Post by hack_edu »

numbsafari wrote: post #43
sparkling wrote: post #17

Semi off-topic, but i am curious. How much of CS fundamentals do you expect a backend (or fullstack) developer to recite in an job interview? I did all CS theory stuff many years ago at university, but i could not pass a interview test full with these CS basics. Isn't it far more important to know how to design a modern, maintainable, scalable web application? Know how an when to cache stuff. How to design a API. How…

> Isn't it far more important to know how to design a modern, maintainable, scalable web application? Know how an when to cache stuff. How to design a API. How do you do that without some basic understanding of computer science-y stuff? How do you define "scalable", how do you measure it? How can you have some intuition about a design before we spend 3 months and many sprints building it first? How do I know when to…

> How do you do that without some basic understanding of computer science-y stuff?

> How do you define "scalable", how do you measure it? How can you have some intuition about a design before we spend 3 months and many sprints building it first?

> How do I know when to cache stuff? Does it matter if I have calls to a remote cache in a tight loop? Should I be using an in-process, out-of-process, or remote cache for a particular piece of data?

You're proving the above poster's exact point. You are putting your weight in applied questions that rest upon the developer's specific experience. This method is the opposite of evaluating people for their ability to memorize a half dozen algorithms and data structures.

In my experience interviewing candidates, asking people to implement a caching algorithm is a distraction to both parties. A much better evaluation is their ability to provide box-arrow diagram and talk it through. This is much more effective towards understanding their thought processes and knowledge. It is also much, much closer to the _real_ day to day of a today's engineer: communication, advocacy, and breadth of knowledge. Code is cheap. Business should screen employees for an interest.

CS textbook questions introduce enormous amounts of bias, especially in panel interviews. It is a dangerous trap that companies use to further entrench their team cliquiness and departmental monoculture. It is ripe for Simple Sabotage. Simply put, its lazy.

Re: Python coding interview challenges

#56

Post by jacquesm »

septimus111 wrote: post #44
cauterized wrote: post #27

I see these challenges as a great way for excellent experienced developers to weed out incompetent companies. I'm a kick-ass get-things-done full-stack web engineer. I've never had to deal with one of these sorts of problems in my day to day work; and if I did, I'd just find an existing, tested, stable library that already handled them. A company that needs someone to solve these sorts of problems doesn't want me on…

I agree that these interviews are often just an annoying rite of passage, and they exclude many very talented programmers, but dismissing companies that use them as 'incompetent' seems like a stretch to me. Learning basic data structures & algorithms is an immensely useful thing for a programmer, and completely essential in many cases. The best of these puzzles are based on problems which people have had to solve in…

It's just laziness incarnate. This pushes all the investment of the first phase of interviewing someone onto an automated process and denies the candidate the opportunity to vet the company which is just as important as the reverse.

Well, actually they do allow the candidate to vet the company: the message they send is we don't care about you at all until you do a bunch of busywork and if you're very lucky we might allow a human to spend some cycles on reviewing your results.

If as a company that is the kind of message you would want your prospective employees to have that's fine with me but it would be good to remember that interviewing a candidate is a two way street.

Re: Python coding interview challenges

#57

Post by collyw »

andrepd wrote: post #42
cauterized wrote: post #27

I see these challenges as a great way for excellent experienced developers to weed out incompetent companies. I'm a kick-ass get-things-done full-stack web engineer. I've never had to deal with one of these sorts of problems in my day to day work; and if I did, I'd just find an existing, tested, stable library that already handled them. A company that needs someone to solve these sorts of problems doesn't want me on…

It's not about actually having to implement these algorithms in your practical, day-to-day work. It's a challenge to test your reasoning and problem-solving ability in abstract, that you can administer in 15 minutes. You can't really test a candidate with real-world workloads, can you.

Why not ask me to bring in some work I have and discuss it?

Re: Python coding interview challenges

#58

Post by x1798DE »

wpietri wrote: post #47
andrepd wrote: post #42

Earlier quoted context omitted.

It's not about actually having to implement these algorithms in your practical, day-to-day work. It's a challenge to test your reasoning and problem-solving ability in abstract, that you can administer in 15 minutes. You can't really test a candidate with real-world workloads, can you.

You absolutely can test a candidate with real-world workloads. It takes longer than 15 minutes, though. I have no idea why anybody cares about the 15-minute thing. Each person you hire adds thousands of hours to your available labor. So even if I spend 100 hours finding the right candidate, I'm still way ahead. And the better my working environment is, the lower my turnover, in which case I can spend even more.

You are often weeding through a large number of applicants, so spending 100 hours on each candidate is just not feasible, and, generally, not necessary. Plus, high quality, experienced developers are not going to want to spend 100+ hours doing real work for companies just to see if they can get a job.

I'm more than happy to spend an hour here or there for a phone screen or coding test to show that I understand the basics of data structures and algorithms and that I can use that information and my reasoning ability to solve problems I haven't seen before.

Re: Python coding interview challenges

#59

Post by rb808 »

digitalsushi wrote: post #6

I'm a C+/B- developer. I've been doing this stuff for touching two decades, and these questions gave me a prickly sweat down my back. There is a part of me that feels very lucky to have plopped onto the Earth right when I did, before there was an organized process to weed me out. I'm entrenched enough that interviews are generally just culture fit interviews. I think I'd need ulcer medicine to get a job with no reput…

If you can get jobs based on a good resume, reputation and culture fit interviews, you're much better than a C+/B- developer.

Re: Python coding interview challenges

#60

Post by gigatexal »

bigmanwalter wrote: post #14
gigatexal wrote: post #10

Earlier quoted context omitted.

Sure I agree as well. That there are so many resources and tools available to answer these coding challenges that if for whatever reason such a challenge was presented the minimum is to be able to answer thr challenge. Going beyond would be to know when to use such a data structure or its inherent strengths and weaknesses etc.

Unless someone can't study these things because they're too busy writing real-world code.

Which is why I think companies doing less whiteboard interviews and more real world coding tests make more sense. I think one could understand the limitations of a linked list and still use the built in data structures and be really competent.
Post reply on HN